Electronically controlled anti-dive suspension apparatus for two-wheeled vehicles

ABSTRACT

An electronically controlled anti-dive suspension apparatus for a two-wheeled vehicle includes a suspension system, a sensor, an electronics module, and an actuator. The sensor mounted to the vehicle senses deceleration of the vehicle due to a braking action and produces an input representative thereof. The electronics module mounted to the vehicle and connected to the sensor receives and processes the input from the sensor and produces an output corresponding to a desired predetermined response to the deceleration of the vehicle. The actuator mounted to the vehicle and coupled to the suspension system receives the output from the electronics module and in response thereto causes the suspension system to reduce its amount of contraction and thereby prevent any resulting dive of the front end of the vehicle downward toward the ground.

This application is a continuation-in-part of application Ser. No.08/991,585, filed Dec. 15, 1997 now U.S. Pat. No. 6,050,583

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to suspension systems fortwo-wheeled vehicles, such as mountain bikes and motorcycles, and, moreparticularly, is concerned with an electronically controlled anti-divesuspension apparatus for actively adjusting the front suspension of thetwo-wheeled vehicle to counteract the initiation of a dive condition dueto “hard” braking by the cyclist.

2. Description of the Prior Art

In recent years suspension systems on bicycles, particularly on mountainbikes, have become more common. Some examples of bicycle suspensionsystems are the ones disclosed in U.S. Pat. No. 4,679,811 to Shuler,U.S. Pat. No. 4,881,750 to Hartmann, U.S. Pat. No. 5,044,648 to Knapp,U.S. Pat. Nos. 5,308,099 and 5,509,674 to Browning, U.S. Pat. Nos.5,445,401 and 5,509,677 to Bradbury, and U.S. Pat. Nos. 5,456,480 and5,580,075 to Turner et al.

A common drawback of most suspension systems is that they are passivemechanical systems which do not sense change in riding conditions norautomatically adjust in response thereto. This results in suspensionsystems that may be too stiff for extremely rocky, steep descents andtoo soft for riding on surfaced roads and bike paths. Some suspensionsystems allow the rider to adjust the pretension on the suspensioncomponents. However, this process normally requires stopping the bicycleto manually make the necessary adjustments. The rider must estimate thestiffness or softness that might be required for the anticipated ridingconditions. Also, the adjustments in some of these systems require theuse of tools.

The above-cited Turner et al. U.S. Pat. No. 5,456,480 contains a cautionto designers that electronic control of bicycle suspensions isimpractical. This statement seems intended to discourage any attempts toimprove bicycle suspensions through the development of anelectronically-based solution to controlling the suspensions in order toadjust to different riding conditions. Nevertheless, it is theperception of the inventor herein that a different approach, possiblyone that is electronically-based, is needed in the design of suspensionsystems for two-wheeled vehicles, such as on mountain bikes andmotorcycles, to improve their handling and performance.

This is especially the case during “hard” braking of the mountain bikeor motorcycle by the cyclist when it is common for the front suspensionto “dive” causing the vehicle to rock forward. Then, once braking hasstopped, the suspension causes the bike to “rock” back. Such rockingmotion can be particularly hazardous for a cyclist on a mountain bikeduring a steep descent which in combination with hard braking can resultin the cyclist flying over the handlebars and for a cyclist on amotorcycle while hard braking prior to entering a sharp corner followedby an acceleration when exiting the corner.

SUMMARY OF THE INVENTION

The present invention provides an electronically controlled anti-divesuspension apparatus for a two-wheeled vehicle designed to satisfy theaforementioned need. The anti-dive suspension apparatus of the presentinvention employs an electronics module, sensor means, actuator meansand power source in conjunction with a front suspension on a two-wheeledvehicle for actively adjusting the front suspension of the two-wheeledvehicle to counteract the initiation of a dive condition due to brakingby the cyclist. The sensor means actively senses the deceleration of thevehicle due to the application of the brakes and produces signalsrepresentative thereof as inputs to the electronics module whichprocesses the inputs and produces an output causing activation of theactuator means to adjust the front suspension system to “stiffen” it soas to prevent its contraction and the resulting dive of the front end ofthe vehicle downward toward the front wheel and thus the ground.

Accordingly, the present invention is directed to a electronicallycontrolled anti-dive suspension apparatus for use on a two-wheeledvehicle. The apparatus comprises: (a) a front suspension system mountedto and between first and second parts of a two-wheeled vehicle movablerelative to and toward one another in response to a braking action beingapplied to the vehicle, the front suspension system including firstmeans connected between the first and second relative movable parts ofthe vehicle and being contractible in response to the first and secondvehicle parts moving toward one another due to the braking action andsecond means connected to the first means for controlling the amount ofcontraction of the first means; (b) means mounted to either one of thefirst and second relative movable parts of the vehicle for sensingdeceleration of the vehicle due to the braking action and producing aninput representative thereof; (c) an electronics module mounted to thevehicle and connected to the sensing means for receiving and processingthe input from the sensing means to produce an output corresponding to adesired predetermined response to the deceleration of the vehicle sensedby the sensing means; (d) at least one actuator mounted to the vehicleand coupled to the suspension system for receiving the output from theelectronics module and in response thereto causing the second means ofthe suspension system to reduce the amount of contraction of the firstmeans and thereby prevent the resulting dive of the front end of thecycle downward toward the ground; and (e) means for electricallypowering the sensing means, the electronics module and the at least oneactuator.

More particularly, the first means of the suspension system includes acylinder having telescoping members defining an interior cavity andrespectively connected to the first and second parts of the vehiclemovable relative to one another and movable toward and away from oneanother between predetermined limits, and an extendable and contractiblespring disposed within the interior cavity being biased to force thetelescoping members away from one another. The second means of thesuspension system includes a fluid contained in the interior cavity anda partition fixed across said interior cavity inside one of thetelescoping members to divide the interior cavity into separate chambersin the telescoping members. The partition defines at least one orificehaving a predetermined size for controlling a rate of flow of the fluidbetween the chambers of the telescoping members so as to control thecontraction of the spring and thereby control the movement of thetelescoping members toward one another. The actuator is coupled to thecylinder of the first means of the suspension system and movablerelative thereto to change the size of the orifice of the partition ofthe second means of the suspension system. The sensing means preferablyis an accelerometer. The electrical powering means preferably is atleast one battery.

These and other features and advantages of the present invention willbecome apparent to those skilled in the art upon a reading of thefollowing detailed description when taken in conjunction with thedrawings wherein there is shown and described an illustrative embodimentof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed description, reference will be made to theattached drawings in which:

FIG. 1 is a diagrammatic representation of an electronically controlledsuspension apparatus which can function as an anti-dive suspensionapparatus in accordance with the present invention when connected to afront suspension of a two-wheeled vehicle.

FIG. 2 is a block diagram of the apparatus.

FIG. 3 is an exploded view of the apparatus.

FIG. 4 is an assembled view of the apparatus.

FIG. 5 is an elevational view of the apparatus of FIG. 4 without theelectronics module.

FIG. 6 is another elevational view of the apparatus rotated 90° from theposition of FIG. 5.

FIG. 7 is a top plan view of the apparatus as seen along line 7—7 inFIG. 6.

FIG. 8 is a diagrammatic view showing a two-wheeled vehicle having afront suspension system to which the apparatus of the present inventioncan be applied.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings and particularly to FIGS. 1 to 4, there isillustrated an electronically controlled suspension apparatus, generallydesignated 10, of the invention of the cross-referenced originalapplication of the inventor herein. Basically, the apparatus 10 includesa suspension system 12, sensing means 14, an electronics module 16, atleast one actuator 18 and an electrical powering means 20 for supplyingelectrical power to the sensing means 14, electronics module 16 andactuator means 18. The suspension system 12 is generally mounted to andextends between parts of a two-wheeled vehicle, such as a bicycle. Forexample, as shown diagrammatically in FIG. 1 the bicycle frame F andbicycle wheel support W pivotally mounted to the bicycle frame F aremovable relative to one another in response to a shock applied to thebicycle. The suspension system 12 could be attached either one or bothof the rear wheel support or front wheel support. In the case of beingattached to the front wheel for performance as the anti-dive suspensionapparatus of the present invention, the support with the suspensionsystem incorporated therein usually is in the form of dual suspensionforks. In the case of being attached to the rear wheel, the suspensionis usually implemented through a pivotal connection to the bicycle frameand to the rear wheel support arm.

The suspension system 12 includes first means 22 connected between theaforementioned parts F, W of the bicycle and capable of absorbing shockapplied to the bicycle and second means 24 connected to the first means22 for controlling the degree of shock absorbing capability of the firstmeans 22. The sensing means 14 is mounted to either one of theaforementioned relative movable parts of the bicycle to which thesuspension system 12 is connected in responding to a shock applied tothe bicycle, and is provided for sensing one, two or all of a pluralityof conditions including forward velocity, tilt and vertical accelerationof the bicycle and producing an input I representative thereof to theelectronics module 16. The electronics module 16 is mounted to thebicycle and connected to the sensing means 14 for receiving the input Lfrom the sensing means 14 and processing the input L to produce anoutput M corresponding to a desired predetermined response to the one,two or all of the conditions sensed by the sensing means 14. Theactuator means 18 is mounted to the bicycle and coupled to thesuspension system 12 for receiving the output M from the electronicsmodule 16 and in response thereto causing the second means 24 of thesuspension system 12 to affect the first means 22 of the suspensionsystem 12 so as to actively adjust the suspension system 12 toaccommodate the immediate surface conditions experienced by a user ofthe bicycle so as to improve control over the riding of the bicycle bythe user under such immediate surface conditions.

Referring now to FIGS. 1 and 3-7, the first means 22 of the suspensionsystem 12 includes a cylinder 26 having outer and inner tubulartelescoping members 28, 30 defining an interior cavity 32 in thecylinder 26 and respectively connected to the parts F, W of the bicyclewhich are slidably movable in telescoping relation with respect to oneanother. The telescoping members 28, 30 of the cylinder 26 are movabletoward and away from one another between predetermined limits. The outertelescoping member 28 of the cylinder 26 has a tubular body portion 28Aopen at one end 28B and closed at the opposite end by a base 28C with athreaded bore 28D defined therethrough. The inner telescoping member 30of the cylinder 26 is made of an upper header tube 34 and a lowerextension tube 36. A head end 36A of the lower extension tube 36 isreceived in and fastened to a bottom end 34A of the upper header tube 34such that the upper header tube 34 and lower extension tube 36 willfunction together as the unitary inner telescoping member 30 of thecylinder 26. Adjacent to the head end 36A of the lower extension tube36, the upper header tube 34 has a plate-like partition 38 fixed acrossthe interior cavity 32 with an aperture 40 defined centrallytherethrough.

The predetermined limit of retraction of the outer and inner telescopingmembers 28, 30 toward one another is established by the head end 36A ofthe lower extension tube 34 of the inner telescoping member 30 engagingthe open end 28B of the outer telescoping member 28. The predeterminedlimit of extension of the outer and inner telescoping members 28, 30away from one another is established by an elongated tension bolt 42 ofthe first means 22 that extends through the central aperture 40 of thepartition 38 and is threaded at its lower end 42A into the threaded bore28D of the base 28C of the outer member 28. The tension bolt 42 has anenlarged head 42B thereon that engages the upper side of the partition38 when the outer and inner telescoping members 28, 30 are fullyextended away from one another as seen in FIGS. 5 and 6. The open end30A of the inner telescoping member 30 opposite from the upper headertube 34 and the open end 28B of the body portion 28A of the outer tube28 both have respective 0-rings 44 mounted thereto for providinghermetic seals between the outer and inner telescoping members 28, 30while accommodating their relative sliding movement. The first means 22also includes an extendable and contractible coil spring 46 disposedwithin the interior cavity 32 of the cylinder 26 being biased to forcethe outer and inner telescoping members 28, 30 to move or extend awayfrom one another.

The second means 24 of the suspension system 12 includes a fluid 48contained in the interior cavity 32 and the aforementioned partition 38fixed across the interior cavity 32 inside the upper header tube 34 ofthe inner telescoping members 30 so as to divide the interior cavity 32into a pair of separate chambers 32A, 32B in the outer and innertelescoping members 28, 30. The partition 38 defines at least one and,preferably, a pair of orifices 50 therethrough on opposite sides of thecentral aperture 40. The orifices 50 are provided with respectivepredetermined sizes for controlling the rate of flow of the fluid 48between the chambers 32A, 32B of the cylinder 26 so as to controlcontraction of the spring 46 and thereby control movement of the outerand inner telescoping members 28, 30 toward one another in absorbing theshock applied to the bicycle. This arrangement is commonly referred toas a variable oil damper. In an exemplary embodiment illustrated inFIGS. 5-7, a pair of orifices 50 are provided through the partition 38,with the size of one of the orifices 50 preferably being greater thanthe size of the other of the orifices 50. For instance, the size of oneorifice 50 may be about half the size of the other orifice 50. However,it should be understood that this is by way of example only, since onlyone orifice 50 can be used to practice the invention.

The sensing means 14 of the apparatus 10 preferably, but notnecessarily, is a biaxial accelerometer, such as a commerciallyavailable Humphrey LA02 device or an Analog Devices ADXL05 device or anAnalog Devices ADXL202 device. The biaxial accelerometer 14 operatesalong two axes disposed in substantially orthogonal or perpendicularrelation to one another. One axis of the accelerometer 14 is orientedparallel to the forward direction of travel of the bicycle along ahorizontal axis H and the other axis is oriented parallel to thegravitational vector along a vertical axis V. The biaxial accelerometer14 along its horizontal axis H measures forward velocity and tilt of thebicycle and along its vertical axis V measures vertical acceleration ofthe bicycle. The measurements along these two axes are combined toproduce the input L representative thereof. The input L includes twosignals, one a DC signal and the other an AC signal. The tilt (T) of thebicycle is determined by the DC signal variation in the H directioncompared to the gravitational vector. From this electrical calculationthe amount of tilt, either inclination or declination, can bedetermined. The forward velocity (FV) is determined by an integration ofthe acceleration in the H direction. The vertical acceleration (VA) isdetermined by direct measurement of the AC signal amplitude in the Vdirection. The vertical acceleration of the bicycle is the principalcondition which indicates the degree of roughness or smoothness of ariding surface and is parallel to the normal force of the ridingsurface.

While a single biaxial accelerometer is the preferred type of sensormeans 14, different combinations of sensors could be used to accomplishthe same sensor input to the electronics module 16. In the case of usingonly the forward velocity and tilt as the input this could beaccomplished using other types of sensing technology. For example, thespeed could be sensed by a Hall effect type sensor attached to one ofthe wheels. The tilt could be sensed using a fluid level sensor.

The electronics module 16 can be a conventional microcontroller, such asa commercially available Motorola MC68HC11 or an Intel 80C51BH, but canbe of any other suitable make. The input L from the sensing means 14,after undergoing amplification and conditioning at block 52 shown inFIG. 2 and then conversion from analog to digital form at block 54 alsoshown in FIG. 2, is provided to the electronics module 16 which thenprocesses the input L and produces output M. The output M adjusts theactuator means 18. It is believed that one of ordinary skill in the artwould be able to program a conventional microcontroller ormicroprocessor to produce the desired output M from the input L withouthaving to exercise an undue amount of experimentation to accomplish thetask. One practical example of a scheme for operation of the electronicsmodule 16 in receiving and processing of the input L and producingoutput M is provided hereinafter. Different combinations of input L andoutput M of this example are shown in Table 1.

As set forth above, the signals making up input L represent the tilt(T), forward velocity (FV) and vertical acceleration (VA) of thebicycle. As mentioned above, the DC signal represents the tilt (T) andhas separate values designated as “o” for when the bicycle is travelingon level ground with an angle of 5 degrees or less, “+” for going up ahill of more than 5 degrees and “−” for going down a hill of more than 5degrees. Combinations of these values for input M are shown in Table 1.As mentioned before, the forward velocity is determined by integratingthe acceleration in H direction and the vertical acceleration is theamplitude of the AC signal in the V direction. The forward velocity (FV)has separate values designated as “−” for when the bicycle has a forwardvelocity in a low range of less than 8 miles per hour, “o” for a midrange of 8 to 15 miles per hour, and “+” for a high range of more than15 miles per hour. The vertical acceleration (VA) has separate valuesdesignated as “−” for when the bicycle is experiencing a verticalacceleration in a low range of less than 0.1 g's, “o” for a mid range of0.1 to 1.0 g's and “+” for a high range of more than 1.0 g's. Thecombinations of these values are also presented in Table 1. As far asthe above ranges of values for tilt, forward velocity and verticalacceleration are concerned, these are given herein as examples only;other ranges could equally be selected for use.

The output M, as mentioned, corresponds to a desired predeterminedresponse to the input L, which represents one, two or all of forwardvelocity, tilt and vertical acceleration of the bicycle. The output Mwill signal the actuator means 18 to either open or to close theorifice(s) 50 depending on the combination of values of the input Lpresented. The closing of the orifice(s) 50 stiffens the suspensionsystem 12, whereas the opening of the orifice(s) 50 softens thesuspension system 12. Also the desired adjustment to the suspensionsystem 12 might be different whether it is associated with the front orrear wheel of the bicycle.

Where a pair of actuators 18 and orifices 50 are employed, the output Mhas four possible combinations of values for an actuator A1 (working onthe smaller size orifice) and an actuator A2 (working on the larger sizeorifice) as follows: “0 and 0”, “1 and 0”, “0 and 1” and “1 and 1” whichrespectively correspond to adjustment to a hard (stiff), half-hard,half-soft and soft suspension for the riding surface being encounteredby the rider. The number bogs means orifice is closed; the number “1”means the orifice is open. The resulting combinations of output M valuescorresponding to the various combinations of input L values are shown inTable 1.

TABLE 1 Input (L) Output (M) No. T FV VA A1 A2 1 o + + 1 1 2 o + − 0 0 3o + o 1 0 4 o o + 0 1 5 o o − 1 1 6 o o o 1 0 7 o − + 0 1 8 o − − 0 0 9o − o 1 0 10 + + + 0 1 11 + + + 0 0 12 + + o 1 0 13 + o + 0 1 14 + o − 00 15 + o o 1 0 16 + − + 1 1 17 + − − 0 0 18 + − o 0 0 19 − + + 0 0 20− + − 1 1 21 − + o 1 0 22 − o + 1 1 23 − o − 0 0 24 − o o 1 0 25 − − + 11 26 − − − 0 0 27 − − o 1 0

A few typical riding environments and corresponding adjustments are asfollows:

(1) Fast cycling on a hard, level surface; referring to No. 2 above, theinput (L) would be: tilt (T) is level (o), forward velocity (FV) is high(+) and vertical acceleration (VA) is low (−); the output (M) would be:close both orifices so A1 and A2 would both be 0. The result is a stiffsuspension system 12 for better handling and more efficient energytransfer to the bicycle wheels.

(2) Slow, steep descent on a rocky single track trail; referring to No.25 above, the input (L) would be: tilt (T) is downhill or negative (−),forward velocity (FV) is low (−) and vertical acceleration (VA) is high(+); the output (M) would be: open both orifices so A1 and A2 would bothbe 1. The result is soft suspension system 12 for better handling ofbicycle. These represent only two possible riding situations. Asmentioned above, the output would likely be different based on whetherthe output is being sent to the front or rear suspension. For example,there may be certain riding situations where a stiff rear suspensionshould be combined with a soft front suspension. This situation wouldoccur during an ascent up a rocky single track trail.

In the illustrated example, the actuator means 18 is a pair of actuators18, such as reciprocable solenoid types, which are operable inconjunction with the pair of orifices 50 of the partition 33 of thesecond means 24 of the suspension system 12. Each actuator 18 is coupledto the cylinder 26 of the first means 22 of the suspension system 12 andmovable relative thereto to change the size of its respective one of theorifices 50 of the partition 38 of the second means 24 of the suspensionsystem 12 to correspondingly change the rate of fluid flow through theorifice 50. Each actuator 18 has a size congruent with the size of theorifice 50 which it moves in relation to. Although the illustratedexample shows a pair of actuators 18 operable in conjunction with thepair of orifices 50, it should be clearly understood that this is onlyone option. Only one actuator 18 operable in conjunction with only oneorifice is another option. Also, each actuator 18 can take other forms,such as a motor and rotary valve instead of a reciprocatory solenoid, ora piezoelectric valve, such as available from ACX of Cambridge, Mass.Also each actuator can be a type which undergoes a proportionate type ofmovement.

The electrical powering means 20 is at least one battery of any suitabletype, such as two AA batteries. As represented respectively by blocks56, 58, 60 in FIG. 2, the apparatus 10 may also have a means forproviding user inputs for overriding the automatic adjustment operation,a display for the electronics module 16 and/or an actuator feedbacksensor. With respect to the user override input 56, the user overridewould be used to set the suspension system 12 to a known stiffnesssetting; for example, for a long ride over pavement the user mightchoose to lock the suspension system 12 in the stiff position. Withrespect to the functions of the display 58, typical informationdisplayed might include, but not limited to the following: batteryindicator; manual suspension settings; maximum speed, tilt and verticalacceleration over the current ride, average speed, etc.

Referring to FIG. 8, the suspension system 12 is shown mounted to andextending between front parts of a two-wheeled vehicle V, such as amountain bike. It also could be mounted to the front of a motorcycle. Inthis application, the suspension apparatus 10 of FIGS. 1-4 is employedto counteract the initiation of a dive condition due to the braking ofthe mountain bike V (or a motorcycle) by the cyclist. The anti-divesuspension apparatus 10 employs the sensor means 14, the electronicmodule 16, at least one actuator 18 and the power source 20, asdescribed above, in conjunction with the front suspension system 12 onthe two-wheeled vehicle V for actively adjusting the front suspensionsystem 12 of the two-wheeled vehicle V in order to counteract theinitiation of the dive condition due to braking by the cyclist. Thefront suspension system 12 is mounted to and between first and secondparts F, W of the two-wheeled vehicle V movable relative to and towardone another in response to the braking action being applied to thevehicle V. The front suspension system 12 includes first means 22connected between the first and second relative movable parts F, W ofthe vehicle V and being contractible in response to the first and secondvehicle parts F, W moving toward one another due to the braking actionand second means 24 connected to the first means 22 for controlling theamount of contraction of the first means 22.

The sensor means 14 is mounted to either one of the first and secondrelative movable parts F, W of the vehicle V for sensing thedeceleration of the vehicle V due to the braking action. The sensormeans 14 can be either a biaxial (H,V) or a single axis (H)accelerometer. In a manner similar to that described above with respectto the various conditions of the bicycle being sensed there, the sensormeans 14 of the anti-dive suspension apparatus 10 actively senses thedeceleration of the vehicle v in the direction of travel H due to theapplication of the brakes and produces signals representative thereof asinputs to the electronics module 16. As an alternative and when thebiaxial accelerometer is being used, deceleration in the direction H canbe sensed along with a downward acceleration in the direction V. Thedownward acceleration also indicates the start of hard braking and of adive condition.

The electronics module 16 is mounted to the vehicle V and connected tothe sensor means 14 for receiving the input from the sensor means 14.The electronics module 16 processes the input and produces an output tothe actuator means 18. The actuator 18 is mounted to the vehicle v andcoupled to the suspension system 12 for receiving the output from theelectronics module and in response thereto for causing the second means24 of the suspension system 12 to adjust the suspension system 12 by“stiffening” it, such as through closing the orifice 50 via operation ofa suspension damping piezoelectric flapper valve. Such stiffeningreduces the amount of contraction that the first means 22 can undergoand thereby prevents the resulting dive of the front end of the vehicleV downward toward its front wheel W and thus the ground. Once thedeceleration is zero, the suspension system 12 is returned to itssetting prior to the braking. It should be understood that the anti-diveapparatus 10 employed here can also be employed on motorcycles toprevent “sit-down” of the rear of the vechicle during acceleration. Fastacceleration of a motorcycle can be sensed and the rear shock absorberstiffened to prevent the sit-down condition.

It is thought that the present invention and its advantages will beunderstood from the foregoing description and it will be apparent thatvarious changes may be made thereto without departing from the spiritand scope of the invention or sacrificing all of its materialadvantages, the form hereinbefore described being merely preferred orexemplary embodiment thereof.

I claim:
 1. An electronically controlled anti-dive suspension apparatusfor use on a two-wheeled vehicle, said apparatus comprising: (a) a frontsuspension system mounted to and between first and second parts of atwo-wheeled vehicle movable relative to and toward one another inresponse to a braking action being applied to the vehicle, said frontsuspension system including (i) first means connected between the firstand second relative movable parts of the vehicle and being contractiblein response to the first and second vehicle parts moving toward oneanother due to the braking action, and (ii) second means connected tothe first means for controlling the amount of contraction of the firstmeans; (b) means mounted to either one of said first and second relativemovable parts of the vehicle for sensing forward velocity and tilt ofthe vehicle in the direction of travel and thereby deceleration of thevehicle due to the braking action and producing an input representativethereof; (c) an electronics module mounted to the vehicle and connectedto said sensing means for receiving and processing the input from saidsensing means to produce an output corresponding to a desiredpredetermined response to the deceleration of the vehicle sensed by saidsensing means; (d) at least one actuator mounted to the vehicle andcoupled to said suspension system for receiving the output from saidelectronics module and in response thereto causing said second means ofsaid suspension system to reduce the amount of contraction of said firstmeans and thereby prevent the resulting dive of the front end of thevehicle downward toward the ground; and (e) means for electricallypowering said sensing means, said electronics module and said at leastone actuator.
 2. The apparatus of claim 1 wherein said first means ofsaid suspension system includes: a cylinder having telescoping membersdefining an interior cavity and respectively connected to the first andsecond parts of the vehicle movable relative to one another, saidtelescoping members being movable toward and away from one anotherbetween predetermined limits; and an extendable and contractible springdisposed within said interior cavity being biased to force saidtelescoping members away from one another.
 3. The apparatus of claim 2wherein said second means of said suspension system includes: a fluidcontained in said interior cavity; and a partition fixed across saidinterior cavity inside one of said telescoping members to divide saidinterior cavity into separate chambers in said telescoping members, saidpartition defining at least one orifice having a predetermined size forcontrolling a rate of flow of said fluid between said chambers of saidtelescoping members so as to control contraction of said spring andthereby control movement of said telescoping members toward one another.4. The apparatus of claim 3 wherein said at least one actuator iscoupled to said cylinder of said first means of said suspension systemand movable relative thereto to change said size of said at least oneorifice of said partition of said second means of said suspensionsystem.
 5. The apparatus of claim 4 further comprising: a pair of saidactuators mounted to the vehicle and coupled to said suspension systemfor receiving said output from said electronics module and in responsethereto causing said second means of said suspension system to affectsaid first means of said suspension system so as to actively adjust saidsuspension system; and a pair of said orifices defined in said partitioneach having a predetermined size for controlling a rate of flow of saidfluid between said chambers of said telescoping members so as to controlcontraction of said spring and thereby control movement of saidtelescoping members toward one another.
 6. The apparatus of claim 5wherein said size of one of said orifices of said partition of saidsecond means of said suspension system is greater than said size of theother of said orifices.
 7. The apparatus of claim 5 wherein each of saidpair of actuators is coupled to said cylinder of said first means ofsaid suspension system and movable relative thereto to change said sizeof one of said orifices of said partition of said second means of saidsuspension system.
 8. The apparatus of claim 1 wherein said sensingmeans is an accelerometer adapted for sensing forward velocity and tiltof the vehicle in the direction of travel.
 9. The apparatus of claim 1wherein said sensing means is a biaxial accelerometer adapted forsensing forward velocity and tilt of the vehicle in the direction oftravel and vertical acceleration of the vehicle.
 10. The apparatus ofclaim 1 wherein said actuator is of a type that undergoes reciprocatingmovement to cause said adjustment of said suspension system.
 11. Theapparatus of claim 1 wherein said actuator is of a type that undergoes apredetermined movement to cause adjustment of said suspension system inproportion to said movement.
 12. The apparatus of claim 1 wherein saidactuator is of a type that undergoes rotary movement to cause saidadjustment of said suspension system.